Transcript winds and Tying it all together

Tying It All Together
Weather and the Sun
Winds
 Equator receives more direct sunlight,
making it warmer.
 This warm air rises to poles, cools, sinks
 Pressure belts around every 30 degrees
latitudes. (bands of high and low pressure)
Winds
 Areas of calm are created when air cools
and sinks (horse latitudes) or warms rapidly
before it moves very far (doldrums).
Global Winds
 Polar Easterlies: from 60-90 degrees
latitudes.
– Formed as cold, sinking air moves from poles to
the south.
– Brings U.S. cold arctic air
Westerlies: 30-60 degrees laittudes
-flow toward poles from west to east.
-US get most weather from these
Global winds
 Trade Winds– 30 degrees latitudes, almost to equator
– Curve to west
– used by traders to sail from Europe to US
 Doldrums
– Around equator (0 degrees)
– Very little wind because warm, rising air creates
low pressure.
Global Winds
 Horse Latitudes
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30 degrees
Sinking air creates high pressure
Causes weak winds
Horses thrown over to save drinking water
 Jet Stream– Narrow belt of high speed winds that blow in upper
Troposphere
– Jets use them to save time: Seattle to Boston, 30
minutes faster than Boston to Seattle
Local Winds
Role of the Sun
 Heats the air, Earth, Ocean
– Warms Earth that warms the air above it.
– Hot air rises, causing: Convection Currents,
warming our atmosphere
– Warms the water: causing the air above the
water to warm the land nearby AND causing
water to evaporate, leading to precipitation
– Causes a temperature change, which causes a
density change, which cause the air pressure to
change. This causes wind.
Role of the Sun
– Wind creates ocean currents that warm the air
above them, warming the land nearby.
– Evaporates water, that water cools, condenses
into clouds. This water falls as precipitation.
Wind
 Unequal Heating of Earth’s surface creates
differences in air pressure.
 Difference in air pressure create wind by areas of
high pressure rushing into areas of low pressure
 Winds curve because of Earth’s rotation. This is
called the Coriolis Effect.
 Winds blow from the equator to the poles in large
convection currents because of the temperature
differences between the equator and the poles.
Air Masses
 Large masses of air form over water, land,
poles, equator
 These air masses bring wet, dry, cold and
warm air
 These masses get picked up by the winds
and moved around
Fronts
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These air masses meet at fronts
THIS is where the weather is not so nice
The air does not mix.
Warm gets pushed up by denser, colder air
Warm air holds more water
This water cools and condenses into clouds
Severe Weather
 Some of these fronts cause severe weather
 Cold fronts ususally start tornadoes and
hurricanes